Amorphous polyarylates induced from 2,2-bis(4-hydroxyphenyl)propane (hereinafter referred to as “bisphenol A”) and terephthalic acid and isophthalic acids are known as engineering plastics. Such polyarylates have high heat resistance and excellent mechanical strength typified by impact strength and dimensional stability, and in addition, amorphous polyarylates are transparent. Therefore, molded articles thereof are widely applied to fields of electricity, electronics, automobiles, machines, etc.
Recently, liquid crystal displays, organic electroluminescence displays and flat panel displays such as electronic papers used in the field of mobile devices such as mobile phones, portable game devices, smartphones and electronic book readers have been designed based on the premise of operation by direct contact with a screen by fingertips. Therefore, a scratch may be caused by scratching by nails at the time of operation or contact with other articles at the time of transportation. For this reason, display members made of high-hardness glass plates were mainly used at first. However, such members are easily broken by impact at the time of sudden fall, shake, twist, etc., and there is a drawback that such members become heavier because the thickness thereof must be increased in order to enhance the strength thereof. For this reason, acrylic resin which is a transparent resin and polycarbonate resin treated with hard coating are used instead of glass (Patent Document 1).
However, with respect to polyarylate resin which has similar transparency, though various polyarylates have been developed, scratch resistance is not necessarily satisfied thereby, and there is a room for improvement (Patent Document 2).
In addition, polyarylates have excellent heat resistance, but melt flowability thereof is exerted only at high temperatures, and at the time of injection molding, it is required to mold such polyarylates at a temperature of 350° C. or higher. Therefore, various additives such as a mold release agent, antioxidant, ultraviolet absorber and dye added to such polyarylates may be decomposed to be accumulated on a mold, or a bubble defect may be generated in resin, and there is a room for improvement of maintenance properties and yield.
Meanwhile, there is a case where compatibility with polyamide and weather resistance were improved by modifying a molecular end of a polyarylate, but there is no description regarding improvement of flowability of the polyarylate alone at the time of molding by heating and melting (Patent Documents 3 and 4). Further, there is a case where toner-cleaning properties of an electrophotographic photoreceptor were improved by using a polyarylate having a long-chain fluoroalkyl group at its molecular end, but this is a case of wet molding, and there is no description regarding improvement of flowability at the time of molding by heating and melting. In addition, since fluorine compounds are expensive, there is a need for improvement of flowability with use of an inexpensive material (Patent Document 5).